Logo Logo
Help
Contact
Switch Language to German
Klier, Lydia; Ziegler, Dorothee S.; Rahimofft, Rene; Mosrin, Marc; Knochel, Paul (2017): Practical Large-Scale Regioselective Zincation of Chromone Using TMPZnCl center dot LiCl Triggered by the Presence or Absence of MgCl2. In: Organic Process Research & Development, Vol. 21, No. 4: pp. 660-663
Full text not available from 'Open Access LMU'.

Abstract

Chromones are efficiently zancated in position C(3) in THF by using the commercially available amide base TMPZnCl center dot LiCl (TMP = 2,2,6,6-tetramethylpiperidyl). Additionally, in the presence of a Lewis acid such as MgCl2, zincation using TMPZnCl center dot LiCl occurs at C(2). These metalation reactions are carried out on a SO mmol scale, and the metalation selectivities have been compared with the corresponding small-scale reactions (2 mmol). The resulting zinc organometallics undergo smooth reactions with various electrophiles, for example, Pd-catalyzed cross-coupling reactions or Cu-catalyzed acylations or allylations.